Shock absorbing mechanism



June 24,1947. Q E, DA1-H 2,422,7l8

` SHOCK ABSORBING MECHANISM Filed July 21, 1944 @j l /5 34 3535 P4 1;'

Patented '.une 24, 1,94?7

SHOCK ABSORBING MECHANISM George E. Dath, Mokena, Ill., assignor to`W. H.

Miner, Inc., Chicago, Ill., a corporation of Dela- Application July 21, 1944, serial No. 545,962

6 Claims.

'I'his invention relates to improvements in shock absorbing mechanisms, and more particularly to shock absorbing mechanisms employed in railway draft riggings.

One object of the invention is to provide simple and efficient shock absorbing mechanisms, especially adapted for railway draft riggings, having initial relatively light resistance to absorb the lighter shocks to which the mechanism is subjected, followed by heavier resistance after a predetermined compression of the mechanism to absorb the heavier shocks.

vOther objects of the invention will more clearly appear from the description and claims hereinafter following.

In the drawing forming a part of this specification, Figure 1 is a horizontal, longitudinal sectional view of a portion of a railway draft rigging, illustrating my improvements in connection therewith. Figure 2 is a front elevational view of the improved shock absorbing mechanism illustrated in Figure 1. Figure 3 is a side elevational Vview of the improved shock absorbing mechanism illustrated in Figure 1. Figure 4 is a transverse, vertica1 sectional view, corresponding substantially to the line 4-4 of Figure 3.

In said drawing, IIl-I indicate channel-shaped center sills of a railway car underframe having the usual front and rear stop lugs II--I I. The inner rend. portion of the drawbar is indicated by I2 and is connected toa yoke I3, of well-known design. The yoke I3 and the parts therewithin are supported by a detachable saddle plate I4, which is secured to the underneath sides of the draft sills. To center the Shock absorbing mechanism, the center sills are provided with guide brackets Iii-I5 on the inner sides thereof. My improved shock absorbing mechanism and the usual front and rear followers I6 and I1 are contained within the yoke I3.

My improved shock absorbing mechanism comprises broadly a hollow friction post A; two friction shoes B-B at the front end of the mechanism; two friction shoes C-C at the rear end of the mechanism; an inner relatively light spring D; and an outer heavier spring E.

The friction post A is in the form of a hollow, tubular member closed at the front end by a transverse wall I8. As clearly shown in Figure 1, the post A is open at its rear end. On the outer side, the post A has a longitudinally extending, cylindrical friction surface I9 with which the shoes B--B and C-C are engaged. At the rear end, the post A is provided with a laterally outwardly projecting, annular stop fiange 20, adapted to cooperate with the shoes C-C'.

The friction shoes B, which are two in number, surroundk the front end portion o-f the friction post A. Each shoe B has a transversely curved friction surface 2I on the inner side thereof cooperating with the friction surface I9 ofthe post. At the forward end, each shoe B is laterally outwardly enlarged, as indicated at 22. The enlargement 22 has a rearwardly extending, outwardly and forwardly inclined wedge face 23 on the outer side thereof. The wedge face 23 is of conical contour. At the forward end, each shoe B has a flat, transverse face k2li al'dapted to be engaged by the front follower I6 during compression of the mechanism.

The friction shoes C are two in number and surround the rear end portion of the post A. Each shoe C has a transversely curved, inner friction surface 2l, which engages with the friction surface I9 at the rear end portion of the post. Each shoe C is laterally outwardly enlarged at the rear end thereof, as indicated at 28, and said enlarged portion of the shoe C is provided with a laterally inwardly projecting flange 29, which serves as an abutment for the rear end of the inner spring D. On the kouter side thereof, the enlargement 28 of the shoe is provided with a wedge face 30, which is outwardly and rearwardly inclined. At the rear end, each shoe C presents a flat, transverse face 3l, which bears on the rear follower I1 of the draft rigging. Each shoe C has a forwardly projecting, lengthwise extending arm 32, provided with a head 33 of T-shape formation at its end, which is engaged in an opening 34 of the corresponding front shoe B. The opening 34 is shaped to receive the arm and the T-head and has rear shoulders 35-35, which are engaged by the head to limit lengthwise separation of the shoes B and C. On the inner side, each shoe C is provided with a transverse groove or slot 25, the front wall 26 of which serves as a stop shoulder cooperating with the flange 29 of the post A to restrict forward or outward movement of the post with respect to the shoes C-C.

The inner spring D is in the form of a relatively light coil and is telescoped within the friction post, having its front and rear ends bearing respectively on the front en d wall I8 of the post A and the lateral flanges 29-29 of the rear shoes C-C. The spring D is preferably under initial compression in the assembled condition of the mechanism.

The outer spring E is in the form of a relatively heavy coil and surrounds the shoes B-B and C-C. The front end coil of the spring E bears on the wedge faces 23-23 of the shoes B-B, and the rear end coil thereof bears on the wedgeY faces 30--39 of the shoes C--C. The spring E is also under a predetermined initial compression and, through its engagementY with the wedge faces of the front and rear shoes, wedges the shoes inwardly against the friction surface of the post A.

In assembling the mechanism, the spring D is rst placed within the hollow post A and the V`33--33 of the arms of the shoesC-C engaged Within the openings 34-34 of the shoes B-B. The mechanism is then permitted to expand, assuming the normal position shown in Figure l, with outward movement of the shoes B-B limited by engagement of the T-heads of the shoes C-C therewith and outward movement of the post; A, in turn, limited by shouldered engagement of the flange 20 thereof with the front end walls of the slots 2,5-25 of the shoes C-C.

The operation of my improved shock absorbing mechanism isv as follows: Upon relative movement of the followers I6 and l1 of the draft rigging toward each other, the mechanism is compressed therebetween, thereby forcing the shoes B+B and the friction post to move inwardly against the resistance of the inner spring D, the post being gripped by the shoes B-B to move in unison therewith, due to the wedging action exerted by the spring E. As the post moves inwardly, light frictional resistance is created between the friction shoes C-C and the friction surface I9 of the post, due to these shoes being wedged inwardly by the spring E. This action continues until the rear end of the post A comes into engagement with the flanges 29--29 of.. the shoes C--C, whereupon inward movement of the post is positively arrested. The shoes B-B are then compelled to move inwardly with respect to the 'post A and the` shoes C'C during the remainder of the compressionstroke of the mechanism, Vwith resultant high frictional resistance between the post and the shoes B-B. Compression of the mechanism is nnally limited by engagement of the front follower I6 with the front end of the post A.

' In release of the mechanism, the parts thereof are restored to the normal position shown in Figure l, bythe expansive actions of the springs Dr vand E, the spring D forcing the, post outwardly until arrested by the shoulders 2li-26 of the shoes C',C, 'and the spring E forcing the shoes B-B forwardly or outwardly away from the shoes C-C until arrested b'y engagement of the T-heads 33--33 of the shoes C-C with the-shoulders 35-35 of the shoes B-B.

I have herein shown and described what I now consider the preferred manner of carrying out my invention, but the same is merely illustrative and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

I claim:

1. In a shock absorbing mechanism, the combination with a hollow friction post, said post having longitudinally extending exterior friction surfaces; of spring means yieldingly opposing inward movement of the post; friction shoes adapted to receive the actuating force and having sliding engagement with the friction surface of the post; means for forcing said shoes against the post including a spring yieldingly opposing inward movement of the shoes; interengaging means on said shoes for limiting outward movement of the shoes away from each other; means for limiting outward movement of the post with respect to the shoes, with the shoes normally amavis projecting outwardly beyond the post; and stop means for arresting inward movement of the post after a predetermined partial compression of the mechanism.

2. In a shock absorbing mechanism, the combination with a hollow friction post, said post having lengthwise extending, exterior friction surfaces; of spring means telescoped within the post and yleldingly opposing inward movement of the post; friction shoes adapted to receive the actuating force and having lengthwise sliding engagement with the friction surfaces of the post; means for limiting outward movement of the shoes away from each other; means for limiting outward movement of the post with respect to the shoes, with the shoes normally projecting beyond the outer4 ends of the post; and stop means for arresting inward movement of the post after a predetermined partial compression of the mechamsm.

3. -In a shock absorbing mechanism, the combination with 'an inwardly movable column element having longitudinally extending friction surfaces; of friction shoes at the front and rear ends of saidcolumn element in sliding engagement therewith, said front and rear shoes hav-ing shouldered engagement with each other to limit lengthwise separation of -said front and rear shoes; spring means yieldingly opposing relative lengthwise movement of the column and said rear shoes; cooperating limiting stops on said column andrear shoes to limit outward movement of said column with respect to said front shoes, with the outer ends of said front shoes normally projecting beyond the end of said column; and yielding means for forcing said shoes against said column, said yielding means lincluding a spring which yieldingly opposes relative lengthwise movement of the Afront and rear shoes toward each other.

4. In va shock absorbing mechanism, the combination with an inwardly movable column element having vlongitudinally extending friction surfaces; of friction 'shoes at the front and rear ends of `said column element in sliding 'engagement therewith, said front and rear shoes having shouldered engagement with eachother to limit lengthwise separation of said front 'and rear shoes; spring -means yieldingly opposing relative lengthwiseV movement of the 'column and said rear shoes; cooperating limiting stopsfon said column and rear shoes to limit outward movement of said column with respect to said front shoes, with the outer ends of said front shoes normally projecting beyond the Yend of said column; and; a spring interposed between said front and rear shoes 'in wedging engagement therewith and yieldingly opposing relative lengthwise movement thereof.

45r In 'a shock absorbing mechanism, the lcombination with an inwardly movable, hollow column `element lhaving longitudinally extending, exterior friction surfaces; of a plurality of friction shoes surrounding the frontend of said co1- umn element and 'having lengthwise sliding engagement therewith; friction shoes surrounding the rearend of said column elementin sliding engagement therewith, said rear shoes corresponding in number to'said front shoes, and each having a forwardly extending arm anchored to the. corresponding vfrontshoe to limit relative lengthwise separation of said front and rear shoes; cooperating stops on said rear shoes and column element for limiting outward movement of the 'column with respect to said front shoes; a spring 'telescopedwithin said column and yieldingly opposing relative 'movement of the same and said rear shoes, said front and rear shoes having inner wedge faces; and a coil spring surrounding said shoes and having wedging engagement at opposite ends with said wedge faces.

6. In a shock absorbing mechanism adapted to be interposed between two members which are relatively movable toward each other, the combination with a column element having longitudinally extending friction surfaces; of a second co1- umn element abutting one of said movable members; friction shoes abutting the other movable member, said shoes having longitudinally extending friction surfaces engaging the friction surfaces of said rst named column element, said first named column element and shoes being movable inwardly of the mechanism in lengthwise direction toward said second named column element, said shoes having movement lengthwise of the mechanism corresponding to the full compression stroke of the mechanism; stop means on said second named column element for limiting outward movement of said first named column element to less than the full compression stroke of the mechanism with the outer end of said rst named column element spaced inwardly from the outer ends of the shoes in the full release position of Vthe mechanism; means yieldingly opposing inward movement of said first named column element with respect to the second named column element; yielding means wedging said shoes against said rst named column element in gripping engagement therewith to move said column element inwardly of the mechanism in unison with said shoes against the resistance of said first named yielding means, said yielding means for said shoes including a spring yieldingly opposing inward movement of said shoes with respect to said second named column element; and additional stop means on said second named column element arresting inward movement of said first named column'element with respect to the second named column element.

GEORGE E. DATH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

